SPR Sensing of Bisphenol A Using Molecularly Imprinted Nanoparticles Immobilized on Slab Optical Waveguide with Consecutive Parallel Au and Ag Deposition Bands Coexistent with Bisphenol A-Immobilized Au Nanoparticles

Abstract

A slab-type optical waveguide (s_OWG)-based microfluidic SPR measurement system for bisphenol A was developed. This s_OWG possesses consecutive parallel gold and silver deposition bands in the line of plasmon flow, allowing two individual SPR signals to be independently obtained as a result of the difference in resonant reflection spectra of these metals. As a molecular recognition element, molecularly imprinted polymer nanoparticles (MIP-Np) were employed and immobilized on the surface of each of the gold and silver deposition bands. The resonant reflection spectra were measured on the MIP-Np-immobilized consecutive parallel gold and silver deposition bands coexistent with BPA-AuNp. The Ag-based SPR spectra showed a red shift (0.7 nm) when free BPA (0.1 mM) was passed over the BPA-AuNp/immobilized MIP-Np complexes formed on the s_OWG, unlike the case for the Au deposition band, while a large excess of BPA induced a blue shift due to the competitive desorption of BPA-AuNp from the immobilized MIP-Np on the s_OWG. By using the proposed detection system, binding events of other small molecules could be monitored in conjunction with the use of MIP-Np and labeled-AuNp.

Molecular imprinting: perspectives and applications

“…Generally, SPR spectroscopy measures the optical dielectric constants of thin films deposited onto noble metal-coated substrates like Au NPs or Ag NPs, which are extremely sensitive to the refractive index changes occurring within a few hundred nanometers from the sensor surface. Moreover, the SPR sensors incorporated with MIPs have been widely used to monitor protein, 623 environmental contaminants, 624 drugs 625 and food. 626 In general, the combination of SPR with electrochemistry or applying the surface-initiated ATRP for grafting polymeric films on the Au chips is a powerful analytical technique.…”

Preparation of core-shell magnetic molecular imprinted polymer with binary monomer for the fast and selective extraction of bisphenol A from milk

“…Due to their outstanding molecular recognition characteristics, the MIPs have drawn much attention in various fields, such as chemical sensing [3], solid phase extraction [4,5], protein recognition [6], and environmental hormone [7]. 4 The choice of functional monomer is very important for the separation selectivity of MIPs.…”

“…Then 2 g Fe3O4 nanoparticles was dispersed in the mixture of 160 mL isopropanol and 40 mL of distilled water, followed by the addition of 3.0 mL ammonium hydroxide (25 wt%) and 6.0 mL TEOS sequentially. The mixture solution was left for 24 h at room7 temperature under continuous stirring. The residual product was collected using an external magnet, and sequentially rinsed three times with ethanol and distilled water.Finally, the Fe3O4@SiO2 microspheres were dried under vacuum at 60 ℃ for 24 h.To prepare Fe3O4@SiO2-Cl, 1.0 g of Fe3O4@SiO2 microspheres was dispersed in a 2.0 mL 4-chloromethyl-phenyl trichlorosilane in 20 mL anhydrous toluene solution.After ultrasonic treatment for 15 min, a solution of triethylamine (0.5 mL) in anhydrous toluene (2.5 mL) was slowly added into the former mixture, and the resulting mixture was heated to reflux for 24 h under nitrogen.…”

Molecularly Imprinted Polymer Waveguides for Direct Optical Detection of Low‐Molecular‐Weight Analytes

“…[ 17,18 ] In optical sensor applications, nanoMIP monolayers were attached to the sensor surface by means of physisorption, [ 19 ] affi nity reactions, [ 20 ] or covalent binding [ 7 ] for the capture of target analyte.…”